So I've been out twice on the 1200 .Once for about 75 miles on smaller roads at lower speeds and the 35 ish mile return was not good for my lower back .I fitted a large gel pad + a sheepskin cover for the 2nd trip as my lower back was torure after 40 some miles .The 2nd time about 90 miles on mostly Motorway /Dual carriageway foing 60/70+ . It was an improvement but still not good .I have forward controls and the rear shocks are on the 2nd but 1 softest settings .I was thinking of getting mid controls so my legs suport my lower back better and stiffening the shocks 1 or 2 settings . Any suggestions how to improve the comfort without spend a gazillion bucks ?

 

Get a back rest. I've had back pain since forever. Back rest was the only thing that made the ride bearable. It may mean a new seat but the relief will be worth it.

 

I had some real low and wide bars on my bike when I first got it, changed them to some 10" zeds and found a huge improvement with comfort. My arms are straight out maybe a little lower than my shoulders and I have forward controls also.

 

Like Tuck1991 said. Backrest solved my back pain issues.

 

You may want to look at Mean City Cycles, they do a great job on seats. They can move you forward or backwards, lower or raise the seating position and they offer various memory foam and gel options. Riding position is what always gets my back so having the seat and handlebars set up for a relaxed riding position works for me. I have done 700+ miles days on one of their seats with great results. I agree on the backrest too, big help.

 

Pick up a set of used big twin air shocks, I got mine for 75 bucks 12 years ago just to try them, they are still on there and always will be, the difference is unbelievable.
There are different lengths from different models so measure yours with no weight on them so you know what model to get, depending on what ones you buy you can raise or lower the back while your at it if you want it higher or lower.
some good info here;
https://www.hdforums.com/forum/sportster-models/1271796-air-shocks.html

 

Take a look at the "triangle" on the DK Customs website. It could just be you are not sitting comfortably.

 

Like said above, a back rest is the best way to improve comfort. A better seat and comfortable bars will also make a huge difference.

 

I just had to get used to it. My back & knees were constantly sore when I first got the bike, and in the beginning of the season it sometimes takes a week to readjust. With that being said, different handlebars, seat, and control position, could make all the difference.

 

Back rest, higher bars that sit you up, and with forward controls, heel rests! You'd be surprised how taking the weight onto your heels helps.